Playtest: Tecnifibre Duramix HD 16

Duramix HD is the latest addition to Tecnifibre’s Team line of strings, which also includes X-Code. Duramix HD is constructed using similar technology to Tecnifibre Promix (which we playtested for the April 2003 issue of RacquetTech magazine) and X-Code (which we playtested for the January 2011 issue of Racquet Sports Industry magazine). In the case of Duramix HD, bundles of polyamide (AKA nylon) microfilaments and bundles of polyester microfilaments are combined using unique technology that encases each bundle in Tecnifibre’s high-density polyurethane (PU HD). Multiple bundles are used to construct the string itself, held together with PU HD. Where Promix had 30 percent polyester and 70 percent polyamide microfibers, and X-Code has 100 percent polyester microfibers, Duramix HD has 50 percent polyester and 50 percent polyamide microfibers.

Tecnifibre’s testing shows there is 22 percent more fatigue on arm muscles with polyester monofilament — along with higher energy requirements — compared to a multifilament nylon. Tecnifibre tells us that Duramix HD is the missing link between their famous polyurethane multifilaments and a polyester monofilament. Duramix HD is 30 percent firmer than nylon, with more power, better dynamics, and better tension retention. Plus, it plays better than polyester monofilaments at lower tensions.

Tecnifibre recommends Duramix HD for players seeking some of the playing characteristics of polyester strings without the potential for arm and wrist problems associated with stiffer strings.

Duramix HD is available in 16 (1.30 mm) and 17 (1.25 mm) gauges in natural only. It is priced from $13 for sets of 40 feet, and $195 for 660-foot reels. For more information or to order, contact Tecnifibre at 888-TFTennis (888-838-3664), or visit tecnifibre.com. Be sure to read the conclusion for more information about getting a free set to try for yourself.

IN THE LAB

We tested the 16-gauge Duramix HD. The coil measured 40 feet. The diameter measured 1.29-1.32 mm prior to stringing, and 1.25-1.26 mm after stringing. We recorded a stringbed stiffness of 76 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 x 18 pattern) on a constant-pull machine.

The string was tested for five weeks by 36 USRSA playtesters, with NTRP ratings from 3.5 to 6.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. Average number of hours playtested was 27.6.

Duramix HD feels soft out of the package and is easy to handle. The RU resin feels almost rubbery, and the string sometimes emits a squeaking noise at the grommets when tensioning the mains. Despite the additional friction, we had no problem weaving the crosses or tying knots. The tip frays like a multifilament, but even without trimming we had no problem with blocked holes.

No playtester broke his sample during stringing, one reported problems with coil memory, none reported problems tying knots, and three reported friction burn.

ON THE COURT

Our playtest team’s scores put Duramix HD as the fifth best Touch/Feel string we’ve tested for publication, and eighth best in the Comfort category. They also rated it 16th best overall in Playability, and 21st best in Power. Rounding out the ratings, Duramix HD scored well above average in Control and Resistance to Movement.

Five playtesters broke the string during the playtest period, one each at five, eight, nine, eleven, and twelve hours.

CONCLUSION

When you see a string score in the top ten for both Touch/Feel and Comfort, you don’t expect it to have any polyester in it. Yet the half-polyester Duramix HD did exactly that. In the Touch/Feel category where it ranks fifth out of 154 playtests, our playtest team scored just behind Tecnifibre’s legendary NRG2 SPL. In the Comfort category where it ranks eighth overall, three of the other strings ahead of it are also from Tecnifibre (X-One Biphase, TGV, and Xr3). With these and its other high scores, Duramix HD’s overall score is well above average. With the introduction of Duramix HD, Tecnifibre does seem to have found the “missing link” between nylon and polyester strings.

Playtester comments

“This is a very comfortable string with above average feel and power. Tension maintenance and resistance to movement are outstanding. This is one of the best multifilaments I’ve used in a long time.” 5.0 male server-and-volley player using Wilson BLX Six One Team strung at 52 pounds CP (Tecnifibre Black Code/Babolat VS Touch 18/16)

“This is comfortable string with great dwell time.” 4.5 male all court player using Wilson K Six One (16x18) strung at 58 pounds LO (Wilson Hollow Core Pro 17)

“Amazing comfort! Touch and finesse shots are very easy to execute, especially at net. This is the best string I have ever tested.” 5.0 male server-and-volley player using Wilson BLX Six One (16x18) strung at 58 pounds LO (Wilson NXT 17)

“Handles stiff, but plays soft. This is a durable string which is above average in most categories.” 4.5 male all court player using Pro Kennex Graphite Acclaim strung at 55 pounds CP (Babolat VS Team 16)

“Excellent durability, control, and comfort. Tension maintenance is the only slight negative.” 5.0 male all court player using Wilson K Six One (16x18) strung at 54 pounds LO (Tecnifibre Black Code 17)

“While power is on the low side, the mix of comfort, control, and feel is outstanding.” 5.5 male all court player using Wilson BLX Six One Tour strung at 55 pounds CP (Luxilon Alu Power 16L)

“This is a comfortable string with excellent durability. While it does not have quite the playability of natural gut, the touch is surprisingly good.” 4.0 male all court player using Volkl V1 Classic MP strung at 55 pounds LO (Natural Gut 16)

“This is a great beginner string because it has high levels of comfort and control. Power is low, which helps keep the ball from flying all over the place.” 4.5 male all court player using Babolat AeroPro Drive strung at 56/59 pounds CP (Genesis Typhoon 17)

“My arm enjoys this multifilament. String movement is very minimal. String savers and higher tensions are advised for big hitters with durability and control issues.” 4.5 male all court player using Wilson K Pro Staff strung at 58 pounds LO (Luxilon Alu Power 16L)

“Average performance, with some notching and buzzing after 3 sets of heavy topspin.” 5.0 male all court player using Wilson BLX Tour strung at 54 pounds CP (Luxilon Alu Power Rough 16L)

“Just when I was ready to sign on the dotted line, this string started to go dead. Perhaps some pre-stretching would extend the remarkable playabiltiy past ten hours. This is worth a second look.” 4.0 male baseliner with heavy spin using Wilson n1 strung at 62 pounds LO (Tecnifibre X One Biphase 17)

“This is a so-so string with decent durability and very little movement.” 4.0 male all court player using Volkl Power Bridge 10 Mid strung at 55 pounds CP (Gosen Polylon SP 17)

“Comfort and playability are on the low end. Touch and spin are satisfactory. This is the kind of string that makes me think I’ve been spoiled by natural gut.” 5.5 male all court player using Babolat Aero Storm Tour strung at 55/53 pounds CP (Natural Gut/Polyester 16/18)

“Initially this string has good pop and comfort. Over time, however, it loses resiliency. After eighteen hours, it goes dead.” 5.0 male all court player using Prince O3 Red MP strung at 56 pounds CP (Prince Synthetic Gut w/Duraflex 17)